Smoke generator using liquid smoke

ABSTRACT

Linear sprayers spray a line of liquid smoke compound on a rotating internally heated stainless steel drum, the amount sprayed and the speed of the drum being such that there is no build up or run-off. The portion of the drum not receiving liquid smoke is continuously cleaned by heat. The smoke thus generated is conveyed to a conventional smoking chamber. The stainless drum is rotated by a motor speed reducer using chain or belt drive to an insulated hub having a metal tire running on rollers to support the drum. The roller arrangement is such as to permit heat expansion. The drum isolates the smoke from the combustion products of a burner inside the drum which is also supported for endwise heat expansion. The combustion products of the burner exit via a separate flue. A timer may be used to keep the drum turning and the burner burning after the spray of liquid smoke on the drum has stopped, in order to provide a final heat cleaning of the drum.

United States Patent Hang SMOKE GENERATOR USING LIQUID Primary Examiner-John J. Camby SMOKE Assistant Examiner-Henry C. Yuen [76] Inventor: Thomas J. Hang, 2214 Franklin St., fii f HOuse Manitowoc, Wis. 54220 [22] Filed: Nov. 15, 1973 [57] ABSTRACT [21] Appl. No.: 416,299 Linear sprayers spray a line of liquid smoke compound on a rotating internally heated stainless steel drum, the amount sprayed and the speed of the drum [52] US. Cl 126/595, 99/482, i26/3i4 being such that there is no build up or The A23!) 1/04 Aolg 13/06 A471 36/38 portion of the drum not receiving liquid smoke is con- Bold /00 tinuously cleaned by heat. The smoke thus generated [58] Fleld of Search 126/595; is conveyed to a conventional smoking chamber The 99/479482, 473; 2l9/27l, 273, 275, 362 stainless drum is rotated by a motor speed reducer 469471; 21/108; /93 426/3 l4* using chain or belt drive to an insulated hub having a 261/92 /89 metal tire running on rollers to support the drum. The roller arrangement is such as to permit heat expan- [56] References cued sion. The drum isolates the smoke from the combus- UNITED STA S TE tion products of a burner inside the drum which is also 354,072 12/1886 Ryan 126/595 uppor ed for endwise heat expansion. The combusl,963,539 6/1934 Zuber 100/93 RP tion products of the burner exit via a separate flue. A 2,515,455 7/1950 Lipton 126/595 timer may be used to keep the drum turning and the 1 1 7/1952 Bishop l00/93 RP burner burning after the spray of liquid smoke on the g fi 426/314 drum has stopped, in order to provide a final heat rou 3,763,767 10/1973 Baker et a1. 99/482 cleanmg of the drum 12 Claims, 2 Drawing Figures F L A I'\ '1' I I 1 '1 I l 51 a l, l I t I" a l 9 L I r iii-IE: Z

4% x50 4g Z2 Z4 6 0 maze SMOKE GENERATOR USING LIQUID SMOKE BACKGROUND OF THE INVENTION It is known to use a hot plate to turn liquid smoke into smoke vapor but the process is unsatisfactory and leads to deposits on the hot plate which are difficult to clean. The device of this invention is largely selfcleaning because of the nature and arrangement of the heat source, the moving surface, and the spray limited to a portion of the heated surface, and has a highly desirable arrangement of parts to accommodate the expansion effects of extreme local heating and to separate the combustion products and the liquid smoke.

SUMMARY OF THE INVENTION The invention comprises a rotating heated surface, liquid supply means applying liquid smoke to a limited portion of the rotating heated surface, a heater for the rotating surface generally beneath the spray pattern and supported for expansion along a shelf. The supports and drive to the heated surface are isolated from the surface itself. Where the surface is a drum, the invention includes roller supports for the drum on an insulated hub driven by a flexible drive. An optional timer structure turns off the liquid smoke supply before turning off the heaters and the drum rotating drive, either cyclically or at the end of the period of use. Various combinations of those features may be used as long as they are such that the rotating surfaces supplied with liquid smoke can be severely heated so that substantially all the liquid smoke is cleaned from the surface continuously by the heat as the surface rotates without destroying it or other parts, and without separate cleaning mechanism.

DRAWINGS FIG. 1 is across sectional view of my device on line l-l of FIG. 2, with parts of the device further broken away to show internal structure.

FIG. 2 is an end view of my device taken from the right end of FIG. 1 with the tank and tank support for the liquid smoke removed for clarity.

DETAILED DESCRIPTION Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. While the best known embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.

As shown in the drawings, my device has a smoke generating chamber 10, which may be insulated and lined with stainless steel for ease of cleaning (not shown). As shown schematically in FIG. 1, chamber is connected by a duct 12 to a smoking chamber 14 in which food is exposed to the smoke for curing or flavor.

A tank 16 of conventional form contains liquid smoke, which is a liquid commercial product manufactured from smoke of the type used for curing foods, and is not itself a part of this invention. A pipe 18 carries the liquid smoke from tank 16 to spray heads 20. The spray heads are also shown schematically, since they may be of conventional types. The heads 20 shown represent a perferred form which produce a linear pattern in which the spray droplets fall in a narrow band of drum 22 parallel to the axis and above burner 24. Some types require a separate air supply, not shown. Heads producing other spray patterns, or which drip or flow the liquid smoke onto drum 22 may also be used but the liquid smoke must all be applied to a limited area of a rotating surface so that only a portion of the surface receives liquid smoke at any one time.

Stainless steel drum 22 is the preferred form of rotating surface because in addition to the cleaning function (due to heating the entire drum while applying liquid smoke only to the upper surface) the drum serves to isolate the heater from the smoke chamber. The drum 22 extends through the end walls 11 of smoke generator cabinet 10 at both ends. It is provided with inner hub flanges 26 at each end, respectively located near end wall 11 and at the end of pipe or drum 22. (See the right end of FIG. 1). An insulating hub 28 is axially restrained by inner flanges 26 and carries outer tire 30 comprising inner and outer flanges 32 and a cylindrical section 34. A motor and speed reducer 36 drives drum 22 through a chain 38 and sprocket 40. If desired, sprocket 40 may be omitted and chain 38 may be replaced by a belt operating directly on tire surface 34. In either case an appropriate drive sprocket or pulley is mounted on the shaft of motor speed reducer 36.

Drum 22 is supported at each end on rollers 42 which carry the drum on cylindrical tire surfaces 34 while allowing the drum to rotate and to expand and contract due to heating and cooling.

Heater 24 is desirably a gas fuel burning device of standard construction in which gas and air are supplied at 44 and 46, mixed, and supplied to combustion units 48 (shown schematically). The end of burner 24 remote from the fuel connections rests on a support 50 on which it is free to slide axially to allow for heat expansion. As shown in FIG. 2 for ease of illustration, a support 50 is at the end of the burner which is supplied with fuel, but in practice that end may be secured, permitting only the left end as shown in FIG. 1 to move on a support 50 as shown. A flue 52 carries combustion gases from the end of pipe or drum 22 remote from the fuel supply upwardly to a chimney or other exhaust means. The bottom of flue 52 may be desirably left open for mingling of cool gases with hot combustion products. The other end of pipe 22 is open and some additional air is pulled into the pipe by the draft from the flue to assist in complete combustion without undue cooling prior to shut-down.

The intense heat on drum 22 and the restricted area and linear pattern of spray are major factors in keeping the drum clean.

Each of liquid smoke pipe 18 (and any air supply associated with nozzles 20), gas pipe 44, air pipe 46, and motor-speed reducer 36, are provided with respectively appropriate and conventional on and off control means 62 of respectively conventional types. Each control 62 is electrically connected to a conventional timer in such fashion (not shown) that timer 60 may be used to control the period of operation of each. Specifically, timer 60 has at least two shut-off settings and is used to shut off pipe 18 (and any air supply) before shutting off pipes 44 and 46 and motor-speed reducer 36. Thus drum 22 continues to turn and burner 24 continues to supply heat for an additional period to insure complete cleaning of the surface of drum 22 of residues. The additional period during which heat is supplied to the rotary surface, but liquid smoke is not, may occur when the entire unit is to be shut down, or may alternate with periods when liquid smoke is supplied through pipe 18. For instance, a 30 second period when 18 is closed may alternate with a 30 second period when 18 is open. Alternatively 18 may be closed while 44, 46, and 36 remain operative for one-half hour at the close of a day of operation.

What is claimed is:

1. In a smoke generator for producing gaseous smoke from liquid smoke concentrate, the improvement comprising: a drum having a metallic surface supported for rotation on an axis, means for supplying liquid smoke concentrate to a restricted portion of said metallic surface, means for rotating said surface, and stationary heating means for heating said surface, whereby to convert said liquid smoke to gaseous smoke and to reduce accumulation of residues on said surface.

2. The device of claim 1 further comprising: means to control said means for supplying liquid smoke concentrate independently, whereby to remove residues from said surface by turning off the liquid smoke supply without turning off said means for heating said surface.

3. The device of claim 2 wherein said control means operates cyclically while said means for heating operates continuously.

4. The device of claim 1 wherein said axis is generally horizontal, said heating means comprising a burner within said drum and vent means shaped to conduct combustion gases away from an end of said drum without mingling with said gaseous smoke.

5. The device of claim 1 wherein said means for supplying liquid smoke concentrate includes spray means having a linear spray pattern impinging on said surface in an area above the axis of rotation.

6. The device of claim 1 wherein said means for supplying liquid smoke concentrate includes spray means having a linear spray pattern impinging on said surface in an area above said means for heating said surface.

7. The device of claim 6 wherein each said spray means produces a spray pattern aligned parallel with said drum axis.

8. The device of claim 1 further comprising: a housing enclosing the major portion of said drum, the ends of said drum extending out of said housing, and means supporting said drum for rotation comprising a cylindrical insulating collar at each said end, and at least a pair of rollers supporting each said collar.

9. The device of claim 8 further comprising: a metal tire on each said insulating collar, said metal tire being substantially wider axially of said drum than said rollers, whereby to permit heat expansion of said drum without interfering with the suspension of said drum for rotation.

10. The device of claim 1, said means for rotating said surface comprising a motor and speed-reducer having an output shaft, and flexible drive means drivingly connecting said output shaft to said surface.

11. The device of claim 1, said means for heating said surface further comprising: A fuel and air supply means, a fuel burning device connected to said fuel and air supply means and extending axially beneath said surface and shaped to provide heat beneath the portion of the surface to which said concentrate is supplied, said fuel burning device having an end and being supported on a shelf at least at said end, said burner end being free to move in an axial direction with respect to said shelf.

12. The device of claim 11 further comprising: means to control starting and stopping of said means for rotating said surface, said means to supplying said liquid smoke concentrate, and said fuel and air supply means, and a timer connected to all of said means for controlling starting and stopping, said timer being effective to stop the means to supply of liquid smoke concentrate before stopping said other means. 

1. In a smoke generator for producing gaseous smoke from liquid smoke concentrate, the improvement comprising: a drum having a metallic surface supported for rotation on an axis, means for supplying liquid smoke concentrate to a restricted portion of said metallic surface, means for rotating said surface, and stationary heating means for heating said surface, whereby to convert said liquid smoke to gaseous smoke and to reduce accumulation of residues on said surface.
 2. The device of claim 1 further comprising: means to control said means for supplying liquid smoke concentrate independently, whereby to remove residues from said surface by turning off the liquid smoke supply without turning off said means for heating said surface.
 3. The device of claim 2 wherein said control means operates cyclically while said means for heating operates continuously.
 4. The device of claim 1 wherein said axis is generally horizontal, said heating means comprising a burner within said drum and vent means shaped to conduct combustion gases away from an end of said drum without mingling with said gaseous smoke.
 5. The device of claim 1 wherein said means for supplying liquid smoke concentrate includes spray means having a linear spray pattern impinging on said surface in an area above the axis of rotation.
 6. The device of claim 1 wherein said means for supplying liquid smoke concentrate includes spray means having a linear spray pattern impinging on said surface in an area above said means for heating said surface.
 7. The device of claim 6 wherein each said spray means produces a spray pattern aligned parallel with said drum axis.
 8. The device of claim 1 further comprising: a housing enclosing the major portion of said drum, the ends of said drum extending out of said housing, and means supporting said drum for rotation comprising a cylindrical insulating collar at each said end, and at least a pair of rollers supporting each said collar.
 9. The device of claim 8 further comprising: a metal tire on each said insulating collar, said metal tire being substantially wider axially of said drum than said rollers, whereby to permit heat expansion of said drum without interfering with the suspension of said drum for rotation.
 10. The device of claim 1, said means for rotating said surface comprising a motor and speed-reducer having an output shaft, and flexible drive means drivingly connecting said output shaft to said surface.
 11. The device of claim 1, said means for heating said surface further comprising: A fuel and air supply means, a fuel burning device connected to said fuel and air supply means and extending axially beneath said surface and shaped to provide heat beneath the portion of the surface to which said concentrate is supplied, said fuel burning device having an end and being supported on a shelf at least at said end, said burner end being free to move in an axial direction with respect to said shelf.
 12. The device of claim 11 further comprising: means to control starting and stopping of said means for rotating said surface, said means to supplying said liquid smoke concentrate, and said fuel and air supply means, and a timer connected to all of said means for controlling starting and stopping, saiD timer being effective to stop the means to supply of liquid smoke concentrate before stopping said other means. 